The present invention relates to a reader and/or writer apparatus, a power feeding system and a communication system for performing power feeding for proximate wireless operation and communication between, for instance, a cash dispenser, electronic money, an automatic ticket checking system, a room entrance/exit management system or a pay telephone and a proximate wireless card, such as a cash card, a credit card, a passenger ticket, a commuting ticket, a coupon ticket, a control card, an IC card, a license or a telephone calling card.
It is already known that, by using light or a magnetic field, electric power can be supplied in a non-contact manner from the power feeding side to a proximate wireless card (IC card).
For example, Japanese Patent No. 2626882 (JP-A-8-263609) discloses a technique related to disposing a metal plate on a back of a coil-shaped antenna to prevent wrong operation such as reading card data from a back of a non-contact card reader, especially a technique for adjusting a distance between the metal plate and the coil-shaped antenna in consideration of the fact that the resonant frequency shifts when the metal plate is disposed.
In non-contact card systems (proximate wireless card systems), cash cards, credit cards, passenger tickets, commuting tickets and the like for use at the gates of railway stations, on buses and exit/entrances are made as IC cards. When the user of such an IC card causes the IC card to pass in a non-contact manner through a reader/writer provided at the gate of a railway station, on a bus or at an exit/entrance, a power feeding wave or a communication wave is radiated from a coil or an antenna of the reader and/or writer, this electromagnetic wave is received and induced by a coil or an antenna on the card side to actuate a circuit on the card side and to detect a signal. In this case, an electric field radiated from the coil or antenna of the reader and/or writer should satisfy the requirement of the Wireless Telegraphy Act (500 xcexcV/m at a distance of 3 m from the reader and/or writer).
However, there is involved the problem that, as the aforementioned requirement of the Wireless Telegraphy Act (500 xcexcV/m at a distance of 3 m from the reader and/or writer) regarding the radiated electric field determines the upper limit of the amperage of the coil or antenna for the reader and/or writer and hence the upper limit of power feeding, it is difficult to feed sufficient power to the IC card. That is, there is involved the problem that sufficient power feeding from the reader and/or writer to the IC card at a desired distance from the reader and/or writer and suppression of a far field prescribed in the Wireless Telegraphy Act is difficult.
In order to solve the aforementioned problems, a first object of the present invention is to provide a reader and/or writer apparatus, a power feeding system and a communication system in a proximate wireless card system arranged so that power which satisfies the requirement of the Wireless Telegraphy Act (500 xcexcV/m at a distance of 3 m from the reader and/or writer apparatus) regarding the radiated electric field can be supplied sufficiently from the reader and/or writer apparatus to the proximate wireless card (IC card).
A second object of the invention is to provide a reader and/or writer apparatus, a power feeding system and a communication system in a proximate wireless card system which performs high-efficiency power feeding by making acceptable an error in the positioning of the IC card proximate to an antenna provided on the reader and/or writer apparatus.
In order to achieve the first object, according to one aspect of the present invention, a reader and/or writer apparatus has of a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to an IC card, and a conductor member for forming a mirror image of the antenna.
According to another aspect of the present invention, a reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating electromagnetic fields both to supply operational power to an IC card and to transmit and/or receive signals for communication to/from the IC card, and a conductor member for forming a mirror image of the antenna.
The just-mentioned the reader and/or writer apparatus according to the present invention comprises a power supply for generating a signal for power feeding, an encoding circuit for encoding inputted transmit data, a modulator for amplitude-modulating the signal obtained from the power supply with a signal obtained from the encoding circuit so that the signal obtained from encoding circuit is superimposed on the signal obtained from the power supply, and a power feeding circuit for feeding power to an antenna on the basis of a signal obtained from the modulator.
According to still another aspect of the present invention, a reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to an IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
According to yet another aspect of the present invention, a reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating electromagnetic fields both to supply operational power to an IC card and to transmit and/or receive signals for communication to/from the IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
The just-mentioned reader and/or writer apparatus according to the invention comprises a power supply for generating a signal for power feeding, an encoding circuit for encoding inputted transmit data, a modulator for amplitude-modulating the signal obtained from the power supply with a signal obtained from the encoding circuit so that the signal obtained from encoding circuit is superimposed on the signal obtained from the power supply, and a power feeding circuit for feeding power to an antenna and an image antenna on the basis of a signal obtained from the modulator.
According to yet another aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this D.C. voltage to an internal circuit of the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to the IC card and a conductor member for forming a mirror image of the antenna.
According to still another aspect of the present invention, a communication system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card and for performing transmission and/or reception of signals for communication to and/or from the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field both to supply operational power to the IC card and to perform transmission and/or reception of signals for communication to and/or from the IC card and a conductor member for forming a mirror image of the antenna.
According to yet another aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this D.C. voltage to an internal circuit of the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field to supply operational power to the IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
According to still another aspect of the present invention, a communication system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card and for performing transmission and/or reception of signals for communication to and/or from the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic field both to supply operational power to the IC card and to perform transmission and/or reception of signals for communication to and/or from the IC card and a spirally shaped or coil-shaped image antenna which constitutes a mirror image of the former antenna.
In the just-mentioned communication system, the reader and/or writer comprises a power supply for generating a signal for power feeding, an encoding circuit for encoding inputted transmit data, a modulator for amplitude-modulating the signal obtained from the power supply with a signal obtained from the encoding circuit so that the signal obtained from encoding circuit is superimposed on the signal obtained from the power supply, and a power feeding circuit for feeding power to an antenna and an image antenna on the basis of a signal obtained from the modulator.
According to still another aspect of the present invention, a reader and/or writer apparatus has an antenna for generating an electromagnetic wave to feed power to an IC card, and a conductor member disposed so that axc2x7tan xcex8 is 0.2 or less where a is a dimension of the antenna in a position where the distance between an outermost element of the antenna and an edge of the conductor member is minimum and xcex8 is an angle formed between the conductor member and a line which connects the outermost component of the antenna with the edge of the conductor member.
In the just-mentioned reader and/or writer apparatus, the antenna both feeds power to the IC card and performs transmission and/or reception of a communication signal to and/from the IC card.
According to still another aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this D.C. voltage to an internal circuit of the IC card, is provided wherein the reader and/or writer apparatus has an antenna for generating an electromagnetic field to supply operational power to the IC card and a conductor member disposed so that axc2x7tan xcex8 is 0.2 or less where a is a dimension of the antenna in a position where the distance between an outermost component of the antenna and an edge of the conductor member is minimum and xcex8 is an angle formed between the conductor member and a line which connects the outermost component of the antenna with the edge of the conductor member.
According to still another aspect of the present invention, a communication system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card and for performing transmission and/or reception of signals for communication to and/or from the IC card, is provided wherein the reader and/or writer apparatus has an antenna for generating an electromagnetic wave to feed power to the IC card, and a conductor member disposed so that axc2x7tan xcex8 is 0.2 or less where a is a dimension of the antenna in a position where the distance between an outermost element of the antenna and an edge of the conductor member is minimum and xcex8 is an angle formed between the conductor member and a line which connects the outermost component of the antenna with the edge of the conductor member.
According to a feature of the present invention, a spirally shaped or coil-shaped antenna for generating an electromagnetic wave to feed power to an IC card and a conductor member for forming a mirror image of the antenna to suppress an electric field intensity at a position at least 3 meters distant from the antenna, are provided.
According to another feature of present invention, a spirally shaped or coil-shaped antenna for generating an electromagnetic wave both to feed power to an IC card and to perform transmission and/or reception of a communication signal to and/or from the IC and a conductor member for forming a mirror image of the antenna to suppress an electric field intensity at a position at least 3 meters distant from the antenna.
According to still another aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this voltage to an internal circuit of the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic wave to feed power to the IC card and a conductor member for forming a mirror image of the antenna to suppress an electric field intensity at a position at least 3 meters distant from the antenna.
According to still another aspect of the present invention, a communication system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card and for performing transmission and/or reception of signals for communication to and/or from the IC card, is provided wherein the reader and/or writer apparatus has a spirally shaped or coil-shaped antenna for generating an electromagnetic wave both to feed power to the IC card and to perform transmission and/or reception of a communication signal to and/or from the IC and a conductor member for forming a mirror image of the antenna to suppress an electric field intensity at a position at least 3 meters distant from the antenna.
In order to achieve the second object, according to an aspect of the present invention, a power feeding system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card, for converting, in the IC card, the fed power to a D.C. voltage and for supplying this voltage to an internal circuit of the IC card, is provided wherein the outermost dimensions of a spirally shaped or coil-shaped antenna, provided in the reader and/or writer apparatus, for generating an electromagnetic field to supply operational power to the IC card is smaller than the outermost dimensions of a spirally shaped or coil-shaped image antenna formed in the IC card.
According to another aspect of the present invention, a communication system for feeding power, using electromagnetic waves, from a reader and/or writer apparatus to an IC card and for performing transmission and/or reception of signals for communication to and/or from the IC card, is provided wherein outermost dimensions of a spirally shaped or coil-shaped antenna, provided in the reader and/or writer apparatus, for generating electromagnetic waves both to supply operational power to the IC card and to perform transmission and/or reception of signals for communication to and/or from the IC card is smaller than outermost dimensions of a spirally shaped or coil-shaped image antenna formed in the IC card.
As has been explained above, according to the above-described configuration, in a reader and/or writer for feeding power to a proximate IC card, using electromagnetic waves (wireless), it is possible to feed, from an antenna of the reader and/or writer to the IC card, power which satisfies the requirements of the Radio Law in every direction and moreover operates the proximate IC card stably.
Also, according to the above-described configuration, in a power feeding system for feeding power from a reader and/or writer to a proximate IC card, using electromagnetic waves (wireless), it is possible to feed, from an antenna of the reader and/or writer to the IC card, power which satisfies the requirements of the Radio Law in every direction and moreover operates the proximate IC card stably.
Also, according to the above-described configuration, in a reader and/or writer for performing power feeding and communication to a proximate IC card, using electromagnetic waves (wirelessly) from a single antenna, it is possible to feed, from an antenna to the IC card, power which satisfies the requirements of the Radio Law in every direction and moreover operates the proximate IC card stably to thereby perform stable communication.
Also, as in the above-described configuration, by providing a conductor plate under the antenna, a shielding effect is achieved, which ensures stable operation free from the effect of the electromagnetic waves (noise) even if a high-frequency electronic circuit is provided further under the conductor plate.
As in the above arrangement, by making smaller the outermost size of the spirally shaped or coil-shaped antenna for generating an electromagnetic field to feed power to the IC card provided in the reader and/or writer apparatus than the outermost size of the spirally or coil-shaped antenna formed in the IC card, an error in the positioning of the IC card provided close to the antenna provided in the reader and/or writer apparatus is acceptable. It is preferable from a standpoint of the number of magnetic fluxes which are interlinked with the antenna of the IC card that the outermost periphery of the antenna of the IC card is h or more larger than the outermost periphery of the antenna of the reader and/or writer apparatus where h is a commnunication distance between the reader and/or writer apparatus and the IC card in a state where the center of the antenna of the reader and/or writer apparatus and the center of the antenna of the IC card conincide substantially.